Does global stoichiometric theory apply to bryophytes? Tests across an elevationsoil age ecosystem matrix on Mauna Loa, Hawaii

1. General hypotheses have related nutrient stoichiometry to physiology and structure for tracheophytes across global resource gradients. These hypotheses have not been tested on bryophytes despite their importance in numerous ecosystem processes. 2. Twelve bryophyte species were sampled across an elevation · soil age matrix representing a dramatic range of climates onMauna Loa, Hawaii. 3. We tested six major hypotheses for the relationship of tissue nutrients to environment and morphology, and for differences in composition between bryophytes and tracheophytes. 4. Results supported stoichiometric theory.Mass-based nutrient concentrations increased with soil nutrient availability; area-based nutrient concentrations increased with irradiance as mediated by bryophyte canopy mass per area; N and P followed the general scaling shown previously for tracheophytes; and P increased and N:P decreased with elevation consistent with increasing cold tolerance. 5. Synthesis. These findings extend the generality of stoichiometric theory, pointing to convergent physiological responses across distantly related lineages, operating across local and global resource gradients.